Apparatus for forming can bodies



Dec. 5, 1967 M. H. c. BUTTERY 3,355,919

APPARATUS FOR FORMING CAN BODIES Filed March 10, 1965 2 Sheets-Sheet 1 IIIIAPJ.

B I j Mm Vi i l 5 Deg. 5, 1967 M.H. c. BUTTERY 3,355,919

APPARATUS FOR FORMING CAN BODIES Filed March 10, 1965 2 Sheets-Sheet 2 Lij 1 n u e n I o r Midael Harm! [Mil /2M5 Buffs/y United States Patent 3,355,919 APPARATUS FOR FORMING CAN BODIES Michael Harcourt Christians Buttery, Bushey Heath, England, assignor to The Metal Box Company Limited,

London, England, a British company Filed Mar. 10, 1965, Ser. No. 438,700 Claims priority, application Great Britain, Mar. 18, 1964, 11,493/64 4 Claims. (CI. 72-51) ABSTRACT OF THE DISCLOSURE Can body forming means including an elongated horn about which can body blanks are shaped to present hooks thereon in position for interengaging in sea-m forming relation, and seam bumping means including a bumper plate having a seam engageable profile conformable upon impact to follow the profile of the horn and the seam being flattened, thereby to provide side seams of substantially uniform thickness along the length of the born. The plate is equipped with two slots extending toward each other from the plate ends, and also two closed slots paralleling and located one over each of the first mentioned slots, the slots serving to permit the plate profile to conform to horn and seam shaping as aforesaid.

This invention relates to apparatus for forming from thin sheet metal a can body which has a side seam formed by interengaging flattened seam-forming hooks, which apparatus includes shaping devices operable to form a body blank about a mandrel or horn cantilevered from a rigid support, a hammer or bumper steel movable towards and away from the mandrel to effect flattening of the seam-forming hooks against the mandrel, and clamping means extending lengthwise of the mandrel and movable towards and away from the mandrel on the side thereof opposite that with which the hammer or bumper steel co-operates in effecting the flattening of the seamforming hooks, said clamping means including a mandrelengaging member supported for movement into and out of engagement with the mandrel at a position adjacent to the free end thereof and opposed to the position of the hammer or bumper steel so that the hammer load is taken up by said horn-engaging member and the mandrel support. Apparatus as just set forth will be referred to below, and in the appended claims, as apparatus of the kind described.

In apparatus of the kind described because during impact the mandrel is supported at the ends thereof there is a tendency for the mandrel to deflect or bow upward lengthwise under the hammer load. This may result in the production of some seams which are not of even thickness throughout the length thereof, the tendency being for the seams to be thicker at the center portions thereof than at the ends. It is a main object of the present invention to provide a means of avoiding or reducing this tendency.

According to the invention apparatus of the kind described is characterised in that the hammer or bumper steel comprises a steel plate which at positions adjacent to the seam opposing profile thereof is provided with slots which extend towards each other from opposite ends of the plate thereby to permit deflection of the end portions of the plate profile during impact against a seam on the horn and the restoration of the profile on movement of the bumper steel away from the mandrel, whereby during said impact the end portions of the profile portion of the plate are permitted to follow the profile of the horn the seam being flattened to provide a side seam of substantially uniform thickness along the length thereof. The permitted 3,355,919 Patented Dec. 5, 1967 movement of the end portions of the bumper steel profile relative to the central portion thereof may be of the order of 0.005 inch.

In order that the invention may be clearly understood one embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which:

FIGURE 1 is a side elevation, partly in section, of apparatus according to the invention, and

FIGURE 2 is -a view, partly in section, looking in the direction of arrow II, in FIGURE 1.

The construction of the mandrel or horn is well known, as are the shaping devices which are arranged to form a body blank about the mandrel, and the means for effecting operation of the shaping devices, being of known construction will not be described herein. The clamping means is described in British patent specification No. 984,253 and will be described herein only insofar as is necessary to the understanding of the present invention.

Referring to the drawings, the mandrel or horn 1 is cantilevered, see FIGURE 1, from a rigid support formed by a machine frame part 2 and the shaping devices comprise the usual shaping members 3, 4, FIGURE 2, the extremities of which, as is customary, are arranged so as to be effective to locate the can body seam forming hooks (not shown) one within the other in the well known manner. The clamping means, indicated generally by the reference numeral 5, FIGURE 1, includes a mandrel-engaging member 6 at a position adjacent to the free end of the mandrel 1, as best shown in FIGURE 1. When the clamping means, preparatory to hammering operation, clamps a body against the top of the mandrel the member 6 is also engaged with the mandrel.

The bumper steel or hammer consists of a hardened and tempered steel plate 7 having a profile 8 which engages the seam-forming hooks to be flattened. At a position adjacent to the profile 8 the plate is provided with slots 9, 10 which extend towards each other from the ends 11, 12 of the plate. In one embodiment of the invention the distance between the profile '8 and the upper edges of the slots is about one and one-half inches, the distance between the top and the bottom of the slots is about onequarter inch, and the permitted movement of the end portions of the profile relative to the central portion thereof during impact is about 0.005 inch.

The bumper steel or hammer is also provided with closed slots '13, 14, said slots 13, 14 are parallel to the slots 9, 10, which in part overlying the slots 9, 10, and being located between the slots 9, '10 and the profile 8 of the bumper steel or hammer, as best shown in FIGURE 1. The slots 13, 14 permit the end faces 11, and 12 of the bumper steel or hammer to be maintained in a vertical attitude and so ensure parallelism of the deflected profile 8 and mandrel during hammering of a seam. The slots 13, 14 also permit the correct load/deflection characteristics for the bumper steel or hammer without over-stressing the material to the point of permanent set. Thus the slots 9, 10 and 13, 14 are the equivalent of pairs of springs op erating in parallel.

The bumper steel or hammer plate 7 is mounted on a carriage 15 which is reciprocable between guides 16, 17, FIGURE 2, and which is connected to the end of a connecting rod 18 mounted on a rotatable crankshaft 19.

On impact of the bumper steel or hammer plate with the seam of a can body the central portion of the mandrel or horn 1, together with the central portion of the seam, tends to bow upwards but with a bumper steel or hammer structure as herein described the slots 9, 10 tend to close so that the central portion of the hammer profile follows the mandrel. By this means the resulting hammered seams tend to be substantially of uniform thickness throughout the length thereof. As the hammer is moved away from the mandrel the hammer profile is restored due to the resiliency of the material of the tempered steel plate causing the slots to again open from the slightly closed condition thereof.

I claim:

1. In apparatus of the character described, the combination of an elongated frame suported horn, means for shaping body blanks having cooperatively engageable seam hooks about the horn to present said hooks in seam forming relation along the horn, and seam bumping means movable towards and from the horn, said seam bumping means including a steel plate having end portions and a profile which opposes the horn where seams are presented therealong, said plate at positions adjacent to said profile being provided with slots which extend towards each other from the ends of the plate thereby to permit deflection of the end portions of the plate profile during impact and the restoration of the profile on movement of said plate away from the horn, whereby during impact against a seam on the horn the end portions of the profile portion of the plate are permitted to allow the profile of the horn and the seam being flattened to provide a side seam of substantially uniform thickness along the length thereof.

2. Apparatus according to claim 1, wherein the per- Initted movement of the end portions of the hammer profile relative to the central portion thereof is of the order of 0.005 inch.

3. Apparatus according to claim 1, wherein the plate is provided with closed slots located between the plate profile and said first-mentioned slots, said closed slots being arranged to be parallel to and in part located one over each of said first-mentioned slots.

4. Apparatus according to claim 2, wherein the plate is provided with closed slots located between the plate profile and said first-mentioned slots, said closed slots being arranged to be parallel to and in part located one over each of said first-mentioned slots.

References Cited UNlTED STATES PATENTS 756,054 3/1904 Reis 72-51 1,811,580 6/1931 Goldsborough 7251 2,656,806 10/1953 LaXo ll3-12 2,878,766 3/1959 Ely 7251 X CHARLES W. LANHAM, Primary Examiner.

K. C. DECKER, Assistant Examiner. 

1. IN APPARATUS OF THE CHARACTER DESCRIBED, THE COMBINATION OF AN ELONGATED FRAME SUPPORTED HORN, MEANS FOR SHAPING BODY BLANKS HAVING COOPERATIVELY ENGAGEABLE SEAM HOOKS ABOUT THE HORN TO PRESENT SAID HOOKS IN SEAM FORMING RELATION ALONG THE HORN, AND SEAM BUMPING MEANS MOVABLE TOWARDS AND FROM THE HORN, SAID SEAM BUMPING MEANS INCLUDING A STEEL PLATE HAVING END PORTIONS AND A PROFILE WHICH OPPOSES THE HORN WHERE SEAMS ARE PRESENTED THEREALONG, SAID PLATE AT POSITIONS ADJACENT TO SAID PROFILE BEING PROVIDED WITH SLOTS WHICH EXTEND TOWARDS EACH OTHER FROM THE ENDS OF THE PLATE THEREBY TO PERMIT DEFLECTION OF THE END PORTIONS OF THE PLATE PROFILE DURING IMPACT AND THE RESTORATION OF THE PROFILE ON MOVEMENT OF SAID PLATE AWAY FROM THE HORN, WHEREBY DURING IMPACT AGAINST A SEAM ON THE HORN THE END PORTIONS OF THE PROFILE PORTION OF THE PLATE ARE PERMITTED TO ALLOW THE PROFILE OF THE HORN AND THE SEAM BEING FLAT- 